WO2009099870A2

WO2009099870A2 - A power supply system for electrical/electronic equipment

Info

Publication number: WO2009099870A2
Application number: PCT/US2009/032364
Authority: WO
Inventors: Vinayakumar Nayak; Sanjeev Pathak; Pulak Purkait; Rahul Dudhe
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2008-01-31
Filing date: 2009-01-29
Publication date: 2009-08-13
Also published as: WO2009099870A9

Abstract

A power supply management technique for a computing system including one or more electrical/electronic devices is disclosed. In one embodiment, a method of providing uninterrupted power supply to one or more electrical/electronic devices includes providing an AC power supply using an AC power supply source to the one or more electrical/electronic devices during normal operation, determining whether there is a stoppage of the AC power supply source, if so, switching the AC power supply provided to the one or more electrical/electronic devices from the AC power supply source to an AC power from an external rechargeable battery system and if not, continue providing the power to the one or more electrical/electronic devices from the AC power supply source.

Description

A POWER SUPPLY SYSTEM FOR ELECTRICAL/ELECTRONIC EQUIPMENT

BACKGROUND

[0001] A power failure, such as a stoppage in power supply, or a fault may occur at any time in a power supply unit in digital equipment, such as personal computers and associated peripheral devices, which uses input from commercial alternating current (AC) power supply. This is especially a problem in rural areas of developing and underdeveloped countries. In busy summer months, typically, the stoppage in power supply can last for nearly 6-8 hours.

[0002] In such a scenario, most of the users are unable to use these electronic devices. Further, if a backup of data in an information processing unit, such as a personal computer, is not stored Ln a nonvolatile storage medium, then it will be lost when such a power failure occurs. If a power failure, interrupt, or a fault continues for a considerable duration (e.g., several tens of milliseconds or more), a personal computer may lose data. [0003] One current solution to this problem is to use an uninterruptable power supply (UPS). If a UPS is used, the supply of power to a personal computer, a server, or a mainframe can be continued when the supply of power from commercial AC power supply is disturbed, interrupted or stopped. That is to say, a computer system can [0004] maintain its normal operation state without an interruption to a user. However, devices that provide such uninterruptible power supply may be bulky, difficult to relocate and can be expensive. Generally, they are used by commercial users. Furthermore, the longer a UPS can supply power, the more expensive it becomes. Therefore, most of the small-scale businesses and domestic users may not be able to afford a UPS, so the possibility of not using the personal computing systems during these power stoppages [0005]

[0006] become greater and also the possibility of such computing systems losing data at the time of power failure or a fault become even greater. [0004] [0007] Another current solution to this problem is to use generators. However, they can be expensive and can take longer time to start. Further, transition from commercial AC power supply to the generator power can be abrupt and can result in loss of data and/or data corruption. Yet another current solution to this problem is to use an inverter. However, the quality of the power generated by the basic inverters can be very poor and may not be suitable for personal computing system and other such digital equipments.

BRIEF DESCRIPTION QF THE DRAWINGS

[0005] [0008] Example embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:

[0006] [0009] FIG. 1 is a block diagram showing a schematic structure of a power supply system, according to one embodiment.

[0007J[0010] FfG. 2 is a process flow illustrating a method of managing power during a stoppage in an AC power supply source using the power supply system, such as those shown in FlG. 1, according to one embodiment.

[0008][0011] FIG. 3 is a process flow illustrating another method of power management obtained using the power supply system shown in FIG. 1, according to one embodiment.

[0009] [0012] Other features of the present embodiments will be apparent from the accompanying drawings and from the detailed description that follows.

DETAILED DESCRIPTION

[0010] [0013] A technique for providing power management for digital equipment is disclosed. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the various embodiments. It will be evident, however, to one skilled in the art that the various embodiments may be practiced without these specific details. [0014]

[0015] The terms "digital equipment", "electronic devices" and "computing systems and associated peripheral devices" are used interchangeably throughout the document. Also, the terms "power management" and "power supply" are used interchangeably throughout the document. Further, the terms "stoppage", "interrupted" and "off' are interchangeably used throughout the document, hi addition, with reference to the term "power supply", the terms "uninterrupted" and "uninterruptible" are used interchangeably throughout the document.

[0012] [0016] FIG. 1 is a block diagram showing a schematic structure of a power supply system 100, according to one embodiment. Particularly, FIG. 1 illustrates a switching logic 110, an external rechargeable battery system 115, and one or more digital equipments, such as a personal computer 150, a monitor 160, and a printer 170 or any other electrical/electronic devices, such as health support systems requiring 1 15 V, 60Hz/230V, 50Hz and not exceeding a power requirement of approximately about 350 watts, coupled to the switching logic 110. Further, FIG. 1 illustrates the external rechargeable battery system 115 including an alternating current (AC) to direct current (DC) converter and battery charger 120, an external rechargeable battery 130, and a DC [0017] to AC converter 140. Furthermore, FIG. 1 illustrates the switching logic 110 connected to a visual display 180 and an emergency alarm 190. In addition, FIG. 1 shows the switching logic 1 10 including a sensor circuit 112. Also, FIG. 1 shows a charger and inverter box (CEB) 117 including the switching logic 110, the AC to DC converter and battery charger 120, the DC to AC converter 140, the visual display 180, and the emergency alarm 190.

[0013] [0018] The power supply system 100 having the external rechargeable battery 130 with a battery backup function provides an uninterrupted power supply (e.g., during an interruption or stoppage of AC power supply source) to one or more digital equipments (e.g., the personal computer 150, the monitor 160, the printer 170 and the like). Although only digital equipments are shown in FIG. 1, it should be noted that any other electrical/electronic devices, such as health support systems and heating systems, [0019] [0020] [0021]

[0022) may be used. In some embodiments, these digital equipments and/or electrical/electronic devices require 115 V, 60Hz/230V, 50Hz and do not exceed a power requirement of approximately about 350 watts.

[0014] [0023] The power supply system 100 includes the switching logic 110. In some embodiments, a first input of the switching logic 1 10 is operatively coupled to an AC power supply source and an output of the switching logic 110 is coupled to the electrical/electronic devices.

(0015] [0024] The power supply system 100 also includes the external rechargeable battery system 115. In some embodiments, an input of the external rechargeable battery system 115 is operatively coupled to the AC power supply source to store power from the [0025] AC power supply source and an output of the external rechargeable battery system 115 is coupled to a second input of the switching logic 110. In these embodiments, the switching logic 110 is configured to provide the uninterruptible AC power supply to the electrical/electronic devices by supplying AC power supply from the AC power supply source when there is no stoppage of the AC power supply source and supplying the AC power supply from the power stored in the external rechargeable battery system 115 upon substantially detecting the interruption or stoppage of the AC power supply source. In some embodiments, the stoppage of the AC power supply source is detected by the sensor circuit 112 in the switching logic 110 using comparator circuit and an I/O controller. In operation, the AC power supply source is converted to either high or low level signal by the comparator circuit, which is then inputted to the I/O [0026] controller for either to switch the power from the AC power supply source to the power stored therein from the external rechargeable battery system 1 15 via the DC to AC converter 140.

[0016] [0027] The external rechargeable battery system 115 includes the AC to DC converter and battery charger 120. The external rechargeable batteTy system 1 15 also includes the external rechargeable battery 130. For example, the external rechargeable battery 130 is a lead acid (Pb-acid) battery. For example, the Pb-acid batteries may vary from 65 AH - 240 AH capacity. [0028] [0029]

[0017] [0030] In some embodiments, an input of the AC to DC converter and battery charger 120 is operatively coupled to the AC power supply source to receive AC power from the AC power supply source and to convert it to IX" power, and an output of the AC [0031] to DC converter and battery charger 120 is coupled to an input of the external rechargeable battery 130. In some embodiments, the input of the external rechargeable battery 130 is coupled to the output of the AC to DC converter and battery charger 120 to receive the DC power for charging the external rechargeable battery 130. [0018] [0032] Further, the external rechargeable battery system 1 15 includes the DC to AC converter 140. In some embodiments, an input of the DC to AC converter 140 is coupled to an output of the external rechargeable battery 130 to receive DC power from the external rechargeable battery 130 and to convert the DC power to AC power, and the output of the DC to AC converter 140 is coupled to the second input of the switching [0033] logic 110 to provide the AC power supply from the power stored in the external rechargeable battery 130.

[0019][0034] In operation, the AC to DC converter and battery charger 120 is a rectifier used to convert alternating current from the AC power supply source to direct current. In the example embodiment illustrated in FIG. 1, the AC to DC converter and battery charger 120 converts the 115V, 60Hz / 230V, 50Hz power supply from the AC power supply source to 12V battery DC power. The purpose of the AC to DC converter and battery charger 120 is to charge the external rechargeable battery 130 when the AC power supply source is on (i.e., when there is no stoppage in the AC power supply source). [0020] [0035] As illustrated in FIG. 1, the AC power supply from the AC power supply source is provided to both the switching logic 110 and the external rechargeable battery system 115 simultaneously, when the AC power supply source is on. In these embodiments, the switching logic 110 provides the AC power supply from the AC power [0036] supply source to the load (e.g., electrical/electronic devices such as the personal computer 150, the monitor 160, the printer 170, health support systems, etc.) when the AC power supply source is on.

[0021] [0037] Further, the DC to AC converter 140 is an inverter used to convert DC power to AC power which drives the load when the AC power supply source is off (e.g., [0038]

[0039] when there is a stoppage/interruption in the AC power supply source). As shown in FIG. 1, the DC to AC converter 140 converts the 12V battery DC power from the external

[0040] rechargeable battery 130 to 115V, 60Hz / 230V, 50Hz power supply when the AC power supply source is off.

[0022] [0041] In operation, the switching logic 110 coupled with the AC power supply source and the external rechargeable battery system 1 15 continuously senses the presence [0042] of the AC power supply from the AC power supply source using the sensor circuit 112. In these embodiments, when the AC power supply source is on, the switching logic 110 supplies the AC power supply from the AC power supply source to the output load. [0023] [0043] When the AC power supply source is off, the switching logic 1 10 supplies the power from the external rechargeable battery system 115 to the load. In one embodiment, the switching logic 110 switches the AC power supply provided to the electrical/electronic devices from the AC power supply source to the external rechargeable battery system 1 15, when the AC power supply source is off. [0024|[0044] Further as shown in FIG. 1, the power supply system 100 includes the visual display 180 coupled to the switching logic 110 to display a battery charge status. The power supply system 100 also includes the emergency alarm 190 coupled to the [0045] switching logic 110 to indicate an alarm condition when the charge status of the external rechargeable battery 130 goes below a threshold value. For example, the threshold value is based on the external rechargeable battery charge status reaching less than or equal to 10% of the fully charged state.

[00251 [0046] In the example embodiment illustrated in FIG. 1, the combination of the AC to DC converter and battery charger 120, the DC to AC converter 140 and the [0047J switching logic 110 forms a charger and inverter box (CIB) 117. In one embodiment, the CIB 117 is an independent device and is compatible with any 12V battery types (e.g., 65AH to 240AH) that are selected depending upon load, backup time and cost. In another embodiment, the CIB 117 further includes the emergency alarm 190 and the visual display 180. [0048] [0049]

[0026] [0050] FIG. 2 is a process flow 200 illustrating a method of managing power during a stoppage in an AC power supply source using a power supply system 100, such as those shown in FIG. 1, according to one embodiment. Particularly, FIG. 2 illustrates the method for providing an uninterrupted power supply to one or more electrical/electronic devices using the power supply system 100 including an external rechargeable battery system 115 with an external rechargeable battery 130. In operation 210, an AC power supply is provided using an AC power supply source to the one or more electrical/electronic devices during normal operation. In these embodiments, a switching logic 110 supplies the AC power directly from the AC power supply source to load (e.g., the personal computer 150, the monitor 160, the printer 170 and/or any general [0051] purpose electronic device), when the AC power supply source is on (i.e., when there is no stoppage in the AC power supply source).

[0027] [0052] In operation 220, the process 200 determines whether there is a stoppage/interruption in the AC power supply source using a sensor circuit 112. If there is the stoppage/interruption in the AC power supply source, then the AC power supply [0053] provided to the one or more electrical/electronic devices is switched from the AC power supply source to an AC power from the external rechargeable battery system 115 in operation 230. If there is no stoppage/interruption in the AC power supply source, then the power is continued to be provided to the one or more electrical/electronic devices from the AC power supply source.

[0028] [0054] FIG. 3 is a process flow 300 illustrating another method of power management obtained using the power supply system 100 shown in FIG. 1, according to [0055] one embodiment. In operation 310, a charge state of the external rechargeable battery system 115 is determined. In operation 320, the charge state of the external rechargeable battery system 115 is displayed using a visual display device 180. [0029] [0056] In operation 330, the process 300 determines whether the charge state is below a threshold value, In some embodiments, the threshold value is based on the external rechargeable battery charge status reaching less than or equal to 10% of the fully charged state. In operation 340, an alarm is generated and a message "battery low" is displayed, when the charge state of the external rechargeable battery system 115 goes [005η

[0058] below the threshold value and the process 300 goes to operation 350. The process 300 goes to operation 350 without performing the operation 340, if the charge state is not [0059] below the threshold value. In operation 350, charging the external rechargeable battery 130 using the AC power supply source is continued, if the AC power supply source is available. In these embodiments, the external rechargeable battery 130 is [0060] continuously charged using the AC power supply source. For example, the external rechargeable battery 130 is a Pb-acid battery.

[0061] In accordance with the above-described procedure, the performance summary of the power supply system 100 with an external rechargeable battery is illustrated as follows. The theoretical calculations for backup time of the 190AH, 12V DC external rechargeable battery can be calculated as follows. The battery VAH is equal to 190 * 12 = 2280. Let the efficiency of the battery be 70%, and then the effective battery VAH is given by 2280*0.7 = 1596.

[0062] Let the typical power consumption of a computer be 120W, monitor be 25 W, and printer be 40W. Therefore the total power consumption is equal to 185 W (i.e., 120W+25W+40W). Let the power factor of the power supply system 100 be 0.8. Therefore, total load is calculated as 231.25 VA (i.e., 185W/0.8) approximately. Further, the backup time of the external rechargeable battery is equal to effective battery VAH divided by total load, i.e., 1596/231.25 = 6 hours 54 minutes. Therefore, the external rechargeable battery can give about 6-8 Hrs of power backup time. Further it can be noted that, any other external rechargeable batteries (i.e., any battery outside of the charger and inverter box (CIB)) of different capacities can be used depending upon the load, backup time and cost.

[0032] [0063] The above-described technique provides a back-up solution to users by giving them flexibility to choose any battery they desire. For example, users can choose from a wide array of batteries, such as a car battery, a commercial battery, a general purpose battery and so on. The users can also choose batteries based on their usage [0064] needs, such as load, backup time, cost, and so on. Also, the users can connect any number of electronic devices to the power management system. Further, the users can connect any type of electronic devices to the power management system. Using the right [0065]

[0066] kind of battery, the power supply system 100 can give the users nearly 6-8 hours of power backup. The above technique provides a cost effective power backup solution to the users in developing and underdeveloped countries where stoppage of AC power supply source is very frequent

10033] [0067] It will be appreciated that the various embodiments discussed herein may not be the same embodiment, and may be grouped into various other embodiments not explicitly disclosed herein.

[0034 j [0068] In addition, it will be appreciated that the various operations, processes, and methods disclosed herein may be embodied in a machine-readable medium and/or a machine accessible medium compatible with a data processing system (e.g., a computer system), and may be performed in any order (e.g., including using means for achieving the various operations). Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.

Claims

What is claimed is:

1. A power supply system for providing an uninterrupted power supply to one or more electrical/electronic devices, the system comprising: a switching logic, wherein a first input of the switching logic is operatively coupled to an AC power supply source and an output of the switching logic is coupled to the one or more electrical/electronic devices; and an external rechargeable battery system, wherein an input of the external rechargeable battery system is operatively coupled to the AC power supply source to store power therefrom, and an output of the external rechargeable battery system is coupled to a second input of the switching logic, wherein the switching logic is configured to provide the uninterruptible AC power supply to the one or more electrical/electronic devices by supplying AC power supply from the AC power supply source when there is no stoppage of the AC power supply source, and supplying the AC power supply from the power stored in the external rechargeable battery system upon substantially detecting a stoppage of the AC power supply source.

2. The power supply system of claim 1, wherein the external rechargeable battery system comprises: an AC to DC converter and battery charger, wherein an input of the AC to DC converter and battery charger is operatively coupled to the AC power supply source to receive AC power therefrom and to convert it to DC power; an external rechargeable battery, wherein an input of the external rechargeable battery is coupled to an output of the AC to DC converter and battery charger to receive the DC power for charging the external rechargeable battery; and a DC to AC converter, wherein an input of the DC to AC converter is coupled to an output of the external rechargeable battery to receive DC power therefrom and to convert it to AC power, and wherein an output of the DC to AC converter is coupled to the second input of the switching logic to provide the AC power supply from the power stored in the external rechargeable battery. 3. The power supply system of claim 2, further comprising: a visual display coupled to the switching logic to display a battery charge status.

4. The power supply system of claim 2, further comprising: an emergency alarm coupled to the switching logic to indicate an alarm condition when a charge status of the external rechargeable battery goes below a threshold value.

5. The power supply system of claim 4, wherein the threshold value is based on the external rechargeable battery charge status reaching less than or equal to 10% of the folly charged state.

6. The power supply system of claim 2, wherein the external rechargeable battery is a Pb-acid battery.

7. A charger and inverter box (CIB) for providing an uninterrupted power supply to one or more electrical/electronic devices, the ClB comprising: a switching logic, wherein a first input of the switching logic is operatively coupled to an AC power supply source and an output of the switching logic is coupled to the one or more electrical/electronic devices; an AC to DC converter and battery charger, wherein an input of the AC to DC converter and battery charger is operatively coupled to the AC power supply source to receive AC power therefrom and to convert it to a DC power, and wherein an output of the AC to DC converter and battery charger is connectable to an external rechargeable battery for charging the external rechargeable battery with the DC power; and a DC to AC converter, wherein an input of the DC to AC converter is connectable to an output of the external rechargeable battery to receive DC power therefrom and to convert it to AC power, and wherein an output of the DC to AC converter is coupled to the second input of the switching logic to provide the AC power supply from the power stored in the external rechargeable battery upon substantially detecting a stoppage of the AC power supply source. δ. The ClB of claim 7, further comprising: a visual display coupled to the switching logic to display a battery charge status. 9. The CIB of claim 7, further comprising: an emergency alarm coupled to the switching logic to indicate an alarm condition when a charge status of the external rechargeable battery goes below a threshold value.

10. The ClB of claim 9, wherein the threshold value is based on the external rechargeable battery charge status reaching less than or equal to 10% of the fully charged state.

1 1. The CIB of claim 7, wherein the switching logic comprises: a sensor circuit for detecting the stoppage of the AC power supply source.

12. A method of providing uninterrupted power supply to one or more electrical/electronic devices, the method comprising: providing an AC power supply using an AC power supply source to the one or more electrical/electronic devices during normal operation; determining whether there is a stoppage of the AC power supply source using a sensor circuit; if so, switching the AC power supply provided to the one or more electrical/electronic devices from the AC power supply source to an AC power from an external rechargeable battery system; and if not, continue providing the power to the one or more electrical/electronic devices from the AC power supply source.

13. The method of claim 12, further comprising: determining a charge state of the external rechargeable battery system; and displaying the charge state of the external rechargeable battery system using a visual display device.

14. The method of claim 12, further comprising: generating an alarm when the charge state of the external rechargeable battery system goes below a threshold value.